Sealing plug insertion systems

ABSTRACT

A sealing system provides for plugging holes in a ferromagnetic tank structure. A tripod has variable length legs for placing on a curved or irregular surface of the tank structure. A permanent magnet assembly is attached to each one of the variable length legs for removably attaching the legs individually to the ferromagnetic tank structure. An actuator is mounted in the tripod for positioning over the hole for movement generally perpendicular to the tank structure in which the hole is located. A clamping plug is mounted on the actuator for insertion into and sealing the hole.

BACKGROUND OF THE INVENTION

This invention relates to devices for plugging holes, and, moreparticularly, to devices for plugging holes in ferromagnetic tanks.

Ferromagnetic tank structures are used throughout the world to storeliquids, many of them hazardous to the environment. A particularlycomplex tank structure is formed by the hull of an ocean-going tanker,where such tankers can be super tankers that carry millions of gallonsof hydrocarbon products, e.g., crude oil, gasoline, and chemicals. Eachyear there are numerous leaks from tankers, barges, and the like, withresulting damage to sensitive ecological systems and pollution ofwaterways. Statistics show that some 16,000 incidents occur each yearwith a release of 41,000,000 gallons released to the environment.

Leaks may occur from a number of sources, such as leaking fittings,small punctures, large tears in the side of the structure, and,increasingly, from fixed or drifting mines. By way of example, U.S. Pat.No. 5,355,824, to Meyer et al., incorporated by reference, teaches aframed bladder structure that can cover a large area and be attached toa ferromagnetic tank, such as the hull of a ship, by permanent magnetsthat be selectively placed in magnetic proximity to the tank surface forholding the framed bladder in place and forming a seal around the leak.In many instances, however, the leak may be from a fitting or fluidoutlet formed in the structure or from a relatively small puncture ofthe tank. Then, a large area seal is not required, and it would bedesirable to have available a simple device for sealing within a fittingoutlet or a puncture.

It will be appreciated that the hydrostatic pressure of the liquidwithin a tank structure or exiting from a fitting outlet may be greaterthan the surrounding hydrostatic pressure. Under this condition it isdifficult or impossible to manually approach and insert a sealing devicewithin the breach or opening. Even a small device cannot be readily heldin position to form a seal.

Accordingly, it is an object of the present invention to provide aninsert for sealing within conventional fitting outlets and puncture-typepenetrations in ferromagnetic tank structures, and particularly shiphulls.

Another object of the present invention is to provide a structure toassist in placing a sealing insert within a fitting outlet orpuncture-type penetration against a hydrostatic pressure head.

One other object of the present invention is to anchor an insertplacement structure to the tank surface while placing the sealinginsert.

Additional objects, advantages and novel features of the invention willbe set forth in part in the description which follows, and in part willbecome apparent to those skilled in the art upon examination of thefollowing or may be learned by practice of the invention. The objectsand advantages of the invention may be realized and attained by means ofthe instrumentalities and combinations particularly pointed out in theappended claims.

SUMMARY OF THE INVENTION

To achieve the foregoing and other objects, and in accordance with thepurposes of the present invention, as embodied and broadly describedherein, the apparatus of this invention may comprise a sealing systemfor plugging holes in a ferromagnetic tank structure. A tripod hasvariable length legs for placing on a curved or irregular surface of thetank structure. A permanent magnet assembly is attached to each one ofthe variable length legs for removably attaching the legs individuallyto the ferromagnetic tank structure. An actuator means is mounted in thetripod for positioning over the hole for movement generallyperpendicular to the tank structure in which the hole is located. Aclamping plug is mounted on the actuator means for insertion into andsealing the hole.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and form a part ofthe specification, illustrate the embodiments of the present inventionand, together with the description, serve to explain the principles ofthe invention. In the drawings:

FIG. 1 is a top pictorial illustration of a tripod structure accordingto one embodiment of the present invention.

FIG. 2 is a side pictorial illustration of a tripod structure accordingto one embodiment of the present invention.

FIGS. 3A and 3B are pictorial illustrations of a cammed magneticassembly detached and attached to a tank structure, respectively.

FIGS. 4A-4E are top views of various magnet assemblies according to oneembodiment of the present invention for attaching a tripod to aferromagnetic tank structure.

FIG. 5 is a cross-section of one embodiment of an expandable clampingplug with an insertion and expanding tool attached to a tripod.

FIG. 6 is a cross-section of one embodiment of an inflatable clampingplug with an insertion tool attached to a tripod.

FIG. 7 is a cross-section of one embodiment of a compressible clampingplug with an insertion and compressing tool attached to a tripod.

FIG. 8 is a cross-section of a clamping plug with a rotating clampingmember.

DETAILED DESCRIPTION OF THE INVENTION

A sealing system is provided for plugging holes in ferromagnetic tankstructures, such as ocean-going tankers, barges, land-based steel tanks,and the like. A structure is attached to the tank structure to center anactuator above a hole in the tank and to permit a force to be exerted tocounter the hydrostatic pressure of the fluid in the tank. The actuatorthen inserts a clamping plug into the hole wherein actuation of the plugserves to clamp the plug within the hole and to seal the hole. It willbe appreciated that holes can be plugged from either the outside of astructure, or the inside of a structure such as a ship hull.

Referring first to FIG. 1, there is shown a pictorial illustration, intop view, of a tripod assembly 10 according to the present invention.Hub assembly 12 acts to hold an actuator assembly, discussed below, andhas mounting brackets 14 depending therefrom to engage tripod legassemblies 16. Each tripod leg assembly 16 is extendible to differentlengths, such as with telescoping tubing 18, but any suitable means forproviding length extensions is acceptable for use herein. A permanentmagnet assembly 26 is rotatably attached to each leg to attach the legto the ferromagnetic tank surface. As described herein, permanent magnetassembly 26 may be formed from a cammed structure, such as described inU.S. Pat. No. 5,192,155 to Meyer, incorporated herein by reference. Inanother embodiment, the cam structure provides equal offsets so thatmagnet assembly 26 attaches to a tank structure without rotation.Another suitable detachable magnet is described in U.S. Pat. No5,355,824, to Meyer et al., incorporated herein by reference, where arotating magnet structure is described to provide a magnetic "short" forreleasing the magnet.

FIG. 2 is a pictorial illustration in side view of tripod assembly 10shown in FIG. 1. Mounting brackets 14 depend from hub assembly 12 andsupport leg assemblies 16 with rotatable supports 20, e.g., a pinassembly. Each leg assembly 16 includes an extendable leg 18, which maybe a telescoping tubing or other form of extendable assembly. Once asuitable length is determined for a leg assembly 16 the leg is locked atthe determined length, such as by locking with extension pin 22. At theend of leg assembly 16 that is opposite rotatable support 20, rotatablemounting 24 permits magnet assembly 26 to rotate into engagement withthe surface of container 28. When magnet assemblies 26 are actuated tomagnetically attach to container 28, tripod assembly 10 is securelyfixed to container 28. It will be appreciated that the extendable androtatable leg assemblies 16 and rotating attachment magnets 26 permittripod assembly 10 to be fixed to a curved or uneven surface while hubassembly 12 is centered over a hole or breach in container 28.

FIGS. 3A and 3B are pictorial illustration in side view of cammed magnetassembly 30 for placing and lifting a magnetic device from the surfaceof a ferromagnetic surface 44. Rotatable arm 32 is formed with handle 31at one end and cam 34 at the other end. When tripod assembly 10 (FIG. 1)is being installed, rotatable arm 32 is locked to tripod leg 40 by,e.g., a locking clip 42, which may be moved along tripod leg 40depending on the final angle configuration. In the locked position, camsurface 36 is rotated to place the long dimension of the cam, which maybe a flat surface 38, in contact with container 44. In the unlockedposition, rotatable arm 32 is rotated to lower magnet 46 into magneticengagement with container 44.

It is a feature of the present invention that a variety of magnetholding strengths may be provided through variations of a basic magnetdesign. Referring now to FIGS. 4A-4E, FIG. 4A is a top view of a basicmagnet assembly 50. In this configuration, handle 52 with cams 54 isrotatably mounted to magnet holder assembly 59, which is sized to hold aselected number of magnets,e.g., three magnets 58, as shown in FIG. 4A.FIG. 4B illustrates the basic magnet assembly 50, with an assembly offive magnets 58 in magnet holder assembly 60.

To further increase the holding strength of the magnets, multiple unitsof basic magnet assembly 50 (FIGS. 4A and 4B) may be assembled, as shownin FIGS. 4C, 4D, and 4E. FIG. 4C indicates frame assembly 62 with twobasic magnet assemblies 50. Mounting bracket 56 provides a rotatablemounting on tripod legs 16 (FIG. 1). FIG. 4D illustrates frame assembly64 for mounting three basic magnet assemblies 50. FIG. 4E illustratesframe assembly 66 for mounting four basic magnet assemblies 50.

In accordance with the present invention, tripod assembly 10 (FIG. 1) isanchored by magnet assemblies 26 to the surface of container structureover a breach in the structure. The anchored tripod assembly 10 is thenused to exert a force needed to insert a seal device into over thebreach. FIG. 5 is a cross-sectional representation of a first plug 70and installation mechanism 68 supported by hub assembly 82 mounted ontripod legs 98. Plug 70 is an expandable plug having an external sealand support 72 for bearing and sealing against the surface of container94 and an expanding grommet 74 that extends through hole or breach 96 incontainer 94. Seal 72 and grommet 74 may be formed as an integral unitfrom any suitable elastomeric material.

In the expanding embodiment shown in FIG. 5, grommet 74 defines agenerally cylindrical cavity having an axis perpendicular to the surfaceof container 94 when installed and open to the interior of container 94.Moveable cone 76 is generally a frusto-conical shape with a small endhaving a diameter that fits within the internal opening of the cylinderdefined by grommet 74 and defining internal threads for acceptingrotatable screw 78. Cone 76 is formed of a rigid material, such asplastic or a corrosion resistant metal. Screw 78 is rotated to draw cone76 into grommet 74 so that the expanding diameter of cone 76 forcesgrommet 74 to expand. As grommet 74 expands, grommet 74 draws seal 72against the surface of container 94 to form a seal and also fills hole96 to form a plug.

Plug installation mechanism 68 functions to both insert plug 70 intohole 96 and to draw cone 76 into grommet 74. Screw 78 extends throughseal cap 72 and terminates at socket 86 that mates with a correspondinghead of shaft 88. Shaft 88 rotates within jack screw 84 and terminatesin external socket 90. Jack screw 84 has external threads that screwthrough internal threads of hub assembly 82 and can be rotated withcrank handle 92. Jack screw 84 also supports and rotates within plughandle 80, which bears against seal 72 to force plug 70 into hole 96. Aconventional socket wrench or the like mates with external socket 90 torotate shaft 88, which, in turn, rotates screw 78 to extend or withdrawcone 76 within grommet 74. Crank 92 is rotated to screw jack screw 84towards container 94 and move plug 70 into sealing engagement with hole96. After cone 76 has been drawn into grommet 74, plug installationmechanism 68 is simply removed from above plug 70 when tripod 98 isremoved from container 94.

FIG. 6 is a cross-section of another embodiment of an expanding plugassembly. Tripod leg assembly 114 supports threaded hub assembly 104above a breach 112 in container 110. In this embodiment, the plug isformed as an expandable bladder 100 with an external socket 103 thatmates with jack screw 106. Crank 108 is fixed to jack screw 106 and isrotated to force bladder 100 within breach 112 so that a first portionof bladder 100 extends through breach 112 and a second portion remainson the outside of container 110. Valve stem 102 is inserted in theexterior portion of bladder 100 so that bladder 100 can be pressurizedafter it is inserted into breach 112. The effect of pressurizing bladder100 is to expand both the first and second portions so that the portionextending through container 110 expands to fill breach 112 and draws thesecond portion against container 110 to form an external seal. Expandingbladder 100 is especially suited for irregularly shaped breaches sincethe bladder can conform to the shape of the breach.

FIG. 7 is a cross-section of a compressible plug 118 that can be used toclamp within and seal a breach of a container 94 of a ferromagneticmaterial. Tripod structure 98 is attached to container 96, as explainedfor FIGS. 1 and 5. Compressible plug 118 is preferably formed from anelastomeric material and includes a seal cap portion 121 and acompressible grommet portion 120. Rigid metal washer 124 is affixed toseal cap portion 121 of plug 118 and serves as a pressure plate forcompressing plug grommet portion 120. A threaded pressure plate 126 isaffixed to grommet portion 120. Threaded bolt 122 extends throughpressure plate 124 and has a head that bears against pressure plate 124.The threads of bolt 122 engage the threads of threaded pressure plate126.

Plug installation mechanism 68 engages plug 118 as explained withreference to FIG. 5 for plug assembly 70. Handle 80 mates with sealingcap 121 and socket 86 engages the head of bolt 122. Bolt 122 isinitially extended through threaded plate 126 so that grommet 120 iselongated with relatively small diameter for inserting into the breachin container 94.

To install plug 118, tripod assembly 98 is magnetically attached tocontainer 94 and plug installation mechanism 68 is centered over thebreach and engaged with plug 118. As explained with reference to FIG. 5,plug 118 is inserted into the breach and bolt 122 is rotated to drawpressure plate 126 toward pressure plate 124 to compress grommet 120. Asgrommet 120 is compressed, the elastomeric material expands, acting todraw seal cap portion 121 against container 94 to form an external sealand to exert a wedging action to clamp plug 118 within container 94.

Yet another embodiment of clamping plug, for use with the tripodassembly 98 and plug installation mechanism 68 described for FIG. 5, isshown in FIG. 8. Clamping seal 130 includes external seal member 136with threaded washer 138 centrally located and fixed to seal member 136.Seal member 136 is preferably formed of an elastomeric materialeffective to seal against the surface of container 140. Threaded shaft134 includes a threaded portion that engages threaded washer 138 and aslotted shank portion that is extendible within a breach throughcontainer 140. Rotating clamp 132 is rotatably fixed within the slottedshank of threaded shaft 134.

Installation mechanism 68 (FIG. 5) may be used to install clamping seal130. Handle 144 is detachably mounted to external seal 136 and ismounted to installation mechanism 68 as shown in FIGS. 5 and 7. Threadedshaft 134 is rotated by installation mechanism 68 so that threaded shaft134 is withdrawn into seal cap 136 to maintain rotating clamp 132parallel with shaft 134 for insertion within a breach in container 140.When shaft 134 is placed within container 140, shaft 134 is rotated toextend rotating clamp 132 into container 140 so that rotating clamp 132is rotated by gravity to a position perpendicular to shaft 134. Shaft134 is then rotated to move rotating clamp 132 to engage the edges ofthe breach in container 140 and compress external seal 136 againstcontainer 140 to form a seal above the breach and to clamp external seal136 to container 140.

It will be understood that the plug devices described herein are notintended to be permanent repairs. In some instances, the plugs may beapplied to a container, e.g., the hull of a ship in a shipyard, to forma temporary seal while repairs on other container components are carriedout. In other instances, the plug is applied at sea to seal a breach,e.g., from a failed component or a failed weld, or from a puncture, sothat the ship can be moved to a shipyard for a permanent repair. Themagnetically attached tripod and screw actuated plug installationassemblies enable a plug to be moved against substantial hydrostaticpressures into a breach and held in position while the plug is actuatedto seal the breach. Each plug includes an external seal portion to sealover the breach and an internal portion acting to clamp the externalseal to the container and, in some instance, to further plug the breach.The clamped plugs are then fixed in place so that the tripod structurecan be removed and the ship moved through the water.

The foregoing description of the preferred embodiments of the inventionhave been presented for purposes of illustration and description. It isnot intended to be exhaustive or to limit the invention to the preciseform disclosed, and obviously many modifications and variations arepossible in light of the above teaching. The embodiments were chosen anddescribed in order to best explain the principles of the invention andits practical application to thereby enable others skilled in the art tobest utilize the invention in various embodiments and with variousmodifications as are suited to the particular use contemplated. It isintended that the scope of the invention be defined by the claimsappended hereto.

What is claimed is:
 1. A sealing system for plugging holes in aferromagnetic tank structure, including:a tripod having variable lengthlegs; a permanent magnet assembly attached to each one of said variablelength legs for removably attaching said legs individually to saidferromagnetic tank structure; actuator means mounted in said tripod forpositioning over said hole for movement perpendicular to said tankstructure in which said hole is located; and a clamping plug assemblymounted on said actuator means for insertion into and sealing said hole.2. A sealing system according to claim 1, wherein said permanent magnetassembly includes:at least one permanent magnet; and a rotatable leverarm connected to said at least one permanent magnet and defining a camsurface for raising and lowering said at least one permanent magnetadjacent said tank structure.
 3. A sealing system according claim 2,wherein said clamping plug assembly includes:a sealing cap for sealingagainst surface portions of said ferromagnetic tank structure adjacentsaid hole; a sealing grommet formed with said sealing cap for insertionwithin said hole, said grommet defining an internal cavity; and a wedgestructure movable within said internal cavity and shaped to expand saidgrommet within said hole as said wedge structure is moved within saidinternal cavity to clamp said sealing cap to said tank structure whileexpanding said grommet within said hole.
 4. A sealing system accordingto claim 2, wherein said clamping plug assembly includes:a sealing capfor sealing against surface portions of said ferromagnetic tankstructure adjacent said hole; a sealing grommet formed with said sealingcap for insertion within said hole, said grommet defining an internalcavity; and a threaded washer engaging said grommet and axially alignedwith said internal cavity.
 5. A sealing system according claim 2,wherein said clamping plug assembly includes:a sealing cap for sealingagainst surface portions of said ferromagnetic tank structure adjacentsaid hole; an inflatable bladder for inserting within said hole; andvalve means connected to said inflatable bladder for introducing aninflating fluid within said bladder to expand said bladder for sealingwithin said hole and clamping said sealing cap above said hole.
 6. Asealing system according to claim 1, wherein said actuator meansincludes a jack assembly for engaging and moving said clamping plugassembly.
 7. A sealing system according to claim 6, wherein said jackassembly includes:a threaded hub assembly supported by said tripod; anda jack screw rotating within said threaded hub assembly for moving saidclamping plug assembly.
 8. A sealing system according to claim 7,wherein said clamping plug assembly includes:a sealing cap for sealingagainst surface portions of said ferromagnetic tank structure adjacentsaid hole; a sealing grommet formed with said sealing cap for insertionwithin said hole, said grommet defining an internal cavity; and a wedgestructure movable within said internal cavity and shaped to expand saidgrommet within said hole as said wedge structure is moved within saidinternal cavity to clamp said sealing cap to said tank structure whileexpanding said grommet within said hole.
 9. A sealing system accordingto claim 7, wherein said clamping plug assembly includes:a sealing capfor sealing against surface portions of said ferromagnetic tankstructure adjacent said hole; a sealing grommet formed with said sealingcap for insertion within said hole, said grommet defining an internalcavity; and a threaded washer engaging said grommet and axially alignedwith said internal cavity.
 10. A sealing system according to claim 7,wherein said clamping plug assembly includes:a sealing cap for sealingagainst surface portions of said ferromagnetic tank structure adjacentsaid hole; an inflatable bladder for inserting within said hole; andvalve means connected to said inflatable bladder for introducing aninflating fluid within said bladder to expand said bladder for sealingwithin said hole and clamping said sealing cap above said hole.
 11. Asealing system according to claim 7, wherein said clamping plug assemblyincludes:a sealing cap for sealing against surface portions of saidferromagnetic tank structure adjacent said hole; a threaded washermounted within said sealing cap; a threaded bolt having an engagingportion extending above said sealing cap, a threaded shaft portionengaging said threaded washer, and a slotted portion having a rotatingarm mounted therein to rotate to a position perpendicular to saidslotted portion when said slotted portion is inserted through said hole.12. A sealing system according to claim 7, wherein said jack screwincludes a rotatable internal shaft for engaging and expanding saidclamping plug assembly.
 13. A sealing system according to claim 12,wherein said clamping plug assembly includes:a sealing cap for sealingagainst surface portions of said ferromagnetic tank structure adjacentsaid hole; a sealing grommet formed with said sealing cap for insertionwithin said hole, said grommet defining an internal cavity; and a wedgestructure movable within said internal cavity and shaped to expand saidgrommet within said hole as said wedge structure is moved within saidinternal cavity to clamp said sealing cap to said tank structure whileexpanding said grommet within said hole.
 14. A sealing system accordingto claim 13, further including a screw having a head portion engagingsaid rotatable internal shaft and a threaded portion engaging said wedgestructure for moving said wedge structure within said internal cavity ofsaid sealing grommet.
 15. A sealing system according to claim 12,wherein said clamping plug assembly includes:a sealing cap for sealingagainst surface portions of said ferromagnetic tank structure adjacentsaid hole; a sealing grommet formed with said sealing cap for insertionwithin said hole, said grommet defining an internal cavity; and athreaded washer engaging said grommet and axially aligned with saidinternal cavity.
 16. A sealing system according to claim 15, furtherincluding a bolt having a head portion engaging said rotatable internalshaft and a threaded portion engaging said threaded washer so thatrotating said bolt moves said threaded washer toward said sealing capover said hole to compress and expand said grommet within said hole. 17.A sealing system according to claim 6, wherein said clamping plugassembly includes:a sealing cap for sealing against surface portions ofsaid ferromagnetic tank structure adjacent said hole; a sealing grommetformed with said sealing cap for insertion within said hole, saidgrommet defining an internal cavity; and a wedge structure movablewithin said internal cavity and shaped to expand said grommet withinsaid hole as said wedge structure is moved within said internal cavityto clamp said sealing cap to said tank structure while expanding saidgrommet within said hole.
 18. A sealing system according to claim 6,wherein said clamping plug assembly includes:a sealing cap for sealingagainst surface portions of said ferromagnetic tank structure adjacentsaid hole; a sealing grommet formed with said sealing cap for insertionwithin said hole, said grommet defining an internal cavity; and athreaded washer engaging said grommet and axially aligned with saidinternal cavity.
 19. A sealing system according claim 6, wherein saidclamping plug assembly includes:a sealing cap for sealing againstsurface portions of said ferromagnetic tank structure adjacent saidhole; an inflatable bladder for inserting within said hole; and valvemeans connected to said inflatable bladder for introducing an inflatingfluid within said bladder to expand said bladder for sealing within saidhole and clamping said sealing cap above said hole.
 20. A sealing systemaccording to claim 6, wherein said clamping plug assembly includes:asealing cap for sealing against surface portions of said ferromagnetictank structure adjacent said hole; a threaded washer mounted within saidsealing cap; a threaded bolt having an engaging portion extending abovesaid sealing cap, a threaded shaft portion engaging said threadedwasher, and a slotted portion having a rotating arm mounted therein torotate to a position perpendicular to said slotted portion when saidslotted portion is inserted through said hole.
 21. A sealing systemaccording to claim 1, wherein said clamping plug assembly includes:asealing cap for sealing against surface portions of said ferromagnetictank structure adjacent said hole; a sealing grommet formed with saidsealing cap for insertion within said hole, said grommet defining aninternal cavity; and a wedge structure movable within said internalcavity and shaped to expand said grommet within said hole as said wedgestructure is moved within said internal cavity to clamp said sealing capto said tank structure while expanding said grommet within said hole.22. A sealing system according to claim 1, wherein said clamping plugassembly includes:a sealing cap for sealing against surface portions ofsaid ferromagnetic tank structure adjacent said hole; a sealing grommetformed with said sealing cap for insertion within said hole, saidgrommet defining an internal cavity; and a threaded washer engaging saidgrommet and axially aligned with said internal cavity.
 23. A sealingsystem according to claim 1, wherein said clamping plug assemblyincludes:a sealing cap for sealing against surface portions of saidferromagnetic tank structure adjacent said hole; an inflatable bladderfor inserting within said hole; and valve means connected to saidinflatable bladder for introducing an inflating fluid within saidbladder to expand said bladder for sealing within said hole and clampingsaid sealing cap above said hole.